re PR debug/42918 ("-fcompare-debug failure" with "-O2 -ftracer" (2))

	PR debug/42918
	* caller-save.c (save_call_clobbered_regs): If BB ends with
	a DEBUG_INSN, move any notes in between last real insn and the last
	DEBUG_INSN after the last DEBUG_INSN.

	* gcc.dg/pr42918.c: New test.

From-SVN: r156823

4 files changed, 66 insertions, 2 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index efb042d..31f251d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2010-02-17  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/42918
+	* caller-save.c (save_call_clobbered_regs): If BB ends with
+	a DEBUG_INSN, move any notes in between last real insn and the last
+	DEBUG_INSN after the last DEBUG_INSN.
+
 2010-02-16  Joern Rennecke  <joern.rennecke@embecosm.com>
 
 	* tm.texi (TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD_GUARD_SPEC):
diff --git a/gcc/caller-save.c b/gcc/caller-save.c
index a6faeea..dbfd42a 100644
--- a/gcc/caller-save.c
+++ b/gcc/caller-save.c
@@ -1,6 +1,6 @@
 /* Save and restore call-clobbered registers which are live across a call.
    Copyright (C) 1989, 1992, 1994, 1995, 1997, 1998, 1999, 2000,
-   2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+   2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
    Free Software Foundation, Inc.
 
 This file is part of GCC.
@@ -754,7 +754,7 @@ setup_save_areas (void)
 void
 save_call_clobbered_regs (void)
 {
-  struct insn_chain *chain, *next;
+  struct insn_chain *chain, *next, *last = NULL;
   enum machine_mode save_mode [FIRST_PSEUDO_REGISTER];
 
   /* Computed in mark_set_regs, holds all registers set by the current
@@ -861,6 +861,7 @@ save_call_clobbered_regs (void)
 		if (TEST_HARD_REG_BIT (hard_regs_saved, regno))
 		  n_regs_saved++;
 	    }
+          last = chain;
 	}
       else if (DEBUG_INSN_P (insn) && n_regs_saved)
 	mark_referenced_regs (&PATTERN (insn),
@@ -874,6 +875,36 @@ save_call_clobbered_regs (void)
 	     remain saved.  If the last insn in the block is a JUMP_INSN, put
 	     the restore before the insn, otherwise, put it after the insn.  */
 
+	  if (DEBUG_INSN_P (insn) && last && last->block == chain->block)
+	    {
+	      rtx ins, prev;
+	      basic_block bb = BLOCK_FOR_INSN (insn);
+
+	      /* When adding hard reg restores after a DEBUG_INSN, move
+		 all notes between last real insn and this DEBUG_INSN after
+		 the DEBUG_INSN, otherwise we could get code
+		 -g/-g0 differences.  */
+	      for (ins = PREV_INSN (insn); ins != last->insn; ins = prev)
+		{
+		  prev = PREV_INSN (ins);
+		  if (NOTE_P (ins))
+		    {
+		      NEXT_INSN (prev) = NEXT_INSN (ins);
+		      PREV_INSN (NEXT_INSN (ins)) = prev;
+		      PREV_INSN (ins) = insn;
+		      NEXT_INSN (ins) = NEXT_INSN (insn);
+		      NEXT_INSN (insn) = ins;
+		      if (NEXT_INSN (ins))
+			PREV_INSN (NEXT_INSN (ins)) = ins;
+                      if (BB_END (bb) == insn)
+			BB_END (bb) = ins;
+		    }
+		  else
+		    gcc_assert (DEBUG_INSN_P (ins));
+		}
+	    }
+	  last = NULL;
+
 	  if (n_regs_saved)
 	    for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
 	      if (TEST_HARD_REG_BIT (hard_regs_saved, regno))
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index e1af8f3..7d3f9bd 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2010-02-17  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/42918
+	* gcc.dg/pr42918.c: New test.
+
 2010-02-16  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* g++.dg/ext/attrib36.C: Require ILP32.
diff --git a/gcc/testsuite/gcc.dg/pr42918.c b/gcc/testsuite/gcc.dg/pr42918.c
new file mode 100644
index 0000000..8a3eef5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr42918.c
@@ -0,0 +1,21 @@
+/* PR debug/42918 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fcompare-debug -ftracer" } */
+
+extern int fi (void);
+extern void fv (void);
+
+int
+f (int i, int j)
+{
+  if (!j)
+    {
+      fv ();
+      goto lab;
+    }
+  i = fi ();
+  if (i == j)
+    fv ();
+lab:
+  return i;
+}